1. Field of the Invention
The present invention is in the area of hand-held striking tools, such as hammers, and pertains more specifically to lightweight hammers.
2. Background of the Invention
Hand-held striking tools, such as claw hammers, have been used for a variety of tasks for centuries. A hammer is basically a force amplifier that works by converting kinetic energy into mechanical work. Claw hammers typically weigh from 7 to 32 ounces, and are used for driving a target into a substrate, such as a nail into wood. The claw portion of the claw hammer also can be used to remove a target, such as a nail, or for ripping apart a substrate, such as wood or pieces of wood.
This type of hammer works as a third-class lever, with the fulcrum or pivot point being the wrist of the user, and the lever arm being the length of the hammer handle. The head, at a distance of the handle from the fulcrum, moves faster than the user's wrist, and this increased speed factored with the weight of the hammer's head and gravity has typically provided the force for driving the target into a substrate.
In the swing that precedes each hammer blow, a certain amount of kinetic energy gets stored in the hammer's head. When the hammer strikes its target, the head gets stopped by an opposite force coming from the target, for example a nail being driven into a piece of wood, which is equal and opposite to the force applied by the head to the target.
The amount of kinetic energy (KE) delivered to the target by the hammer blow is equivalent to the mass of the head (m) times the square of the head's speed (v2) at the time of impact, or KE=0.5*m*v2. Increasing the speed of the hammer's head when it strikes a target exponentially increases the kinetic energy delivered to the target, thereby increasing the amount of work done with each strike of the hammer.
One way to increase the speed of the hammer's head is to increase the length of the hammer's handle. However, it is typically more difficult to accurately squarely hit a nail with a longer handled than a shorter handled hammer. Using a longer hammer may also be awkward or impossible in close spaces.
Another way to increase the hammer head's speed is to lighten the weight of the hammer itself, thereby increasing the potential speed with which a user can swing the hammer. Such a lighter hammer can then be swung faster through the arc defined by the length of the hammer's handle rotating about the fulcrum, which is typically a user's wrist.
Prior art has introduced light weight materials into the heads and handles of hammers to increase hammer speed. The drawbacks of many such materials include malleability, high cost, brittleness, tempering, vibration transmitted to the hand of the user and overall lack of durability.
The present invention comprises graphite and titanium regions in the handle that provide for flexibility and an increased strength to weight ratio.
When a hammer's handle has an increased strength to weight ratio, the weight of the head can be reduced somewhat, but the invention maintains the “head-weight” that carpenters are used to. While graphite alone is lightweight, it must be protected with titanium strike surfaces below the head of the hammer and also at the “butt” end of the handle, which is sometimes used as a striking surface. It is the object of the invention to provide a lightweight yet durable hammer that allows the user to increase the work performed by each hammer blow due to the lightness of weight of the hammer itself, and more particularly due to the strength to weight ratio of the hammer's handle.
It is a further object of the invention to provide a hammer that does not unpleasantly vibrate in the hand of the user, and that will neither dent nor crack under normal use, including when the user mis-strikes a surface and the blow lands on the handle of the hammer instead of the striking surface of the hammer's head.
It is a still further object of the invention to provide these qualities in a relatively inexpensive hammer.
It is a still further object of the invention to provide a method of assembling or manufacturing said hammer.